Aerobic Exercise Improves Cardio Fitness Without Raising Inflammation, Study Reports

Twelve weeks of aerobic exercise improved cardiovascular and respiratory fitness in systemic lupus erythematosus (SLE), but without positive changes in arterial stiffness that was this small study’s main goal.

Results also found no increase in signs of inflammation or oxidative stress in the exercise group compared to a control group urged to adopt a healthier lifestyle.

The study, “Effects of 12-week Aerobic Exercise on Arterial Stiffness, Inflammation, and Cardiorespiratory Fitness in Women with Systemic LUPUS Erythematosus: Non-Randomized Controlled Trial,” appeared in the Journal of Clinical Medicine.

The incidence of heart disease in SLE patients is significantly higher than in healthy people, possibly because of risk factors associated with autoimmunity, such as systemic inflammation and oxidative stress (an excess of damaging free radicals in cells).

Arterial stiffness, an early indicator of atherosclerosis and heart disease, is also higher than usual in lupus patients, and lessening such stiffness is sought to avoid developing heart disease independent of other risk factors.

Regular exercise is known to reduce the risk of heart disease in the general population, and some studies suggest it is of benefit for SLE patients, and could help to reduce arterial stiffness.

But no studies have directly assessed the relationship between regular exercise and risk or heart disease in these patients.

Researchers in Spain designed a non-randomized controlled trial (NCT03107442) to evaluate whether moderate to intense aerobic exercise (also known as cardio) could reduce lupus patients’ risk of heart disease. Specifically, they examined cardiorespiratory fitness and some risk factors for cardiovascular disease, including arterial stiffness, inflammation, and oxidative stress.

The study enrolled 58 women diagnosed with SLE for more than a year and with stable disease for at least six months. Patients had not taken any biological treatments [like Rituxan (rituximab) or Benlysta (belimumab)], did not need prednisone, and had no pre-existing heart disease.

Twenty-six women in the treatment group did two, 75-minute treadmill sessions of gradually increasing intensity each week for 12 weeks, while the 32 women in the control group were encouraged to follow a healthy lifestyle.

In total, 22 of the 26 finished at least 75% of exercise sessions and were included in the analyses. Four control-group patients dropped out of the study.

After 12 weeks, researchers saw no significant differences in arterial stiffness, inflammation, and oxidative stress markers between the two groups.

“The volume, duration, and intensity of exercise might play a relevant role in its effects on arterial stiffness, [so] it seems plausible that 12 weeks of intervention might not have been enough time to modify the elasticity of the arteries,” researchers said.

However, patients in the exercise group showed significant improvement in their cardiorespiratory fitness, measured via a stress test.

Estimating the clinical relevance of changes in the fitness of SLE patients is difficult, because no specific formulas exist for this population.

Researchers instead used parameters for healthy individuals, and found clinically relevant difference in fitness between the two groups.  These differences were comparable to the 13% to 15% reduction in the risk of dying from cardiovascular disease, and 10% to 30% lower risk of any adverse cardiovascular event, found in healthy adults who exercise regularly, they said.

Progressive aerobic exercise may be of benefit to lupus patients by improving their cardiovascular fitness, the study noted.

“The results of this study suggest that 12 weeks of progressive treadmill aerobic exercise … increases cardiorespiratory fitness without exacerbating arterial stiffness, inflammation, or oxidative stress in women with SLE with mild/inactive disease,” the researchers concluded.

This study’s small patient population, short follow-up time, and lack of randomization, however, are limitations on its findings. “Future clinical trials with larger sample sizes are needed to enhance our understanding of how different durations, types, volumes, and exercise intensities might affect vascular health and inflammation in [SLE patients],” they added.